peter slavich rice husk biochar improves productivity of sandy soils

Rice husk biochar improves productivity of sandy soils in

Central Coastal Vietnam

Peter Slavich, Tran Tien Dung, Brad Keen and Hoang Minh Tam

NSW Department of Primary Industries, WollongbarCentre for Coastal Agricultural Landscapes, Southern Cross UniversityAgricultural Science Institute for Southern Central Coastal Vietnam

Australian Centre for International Agricultural Research

Biochar activities in Vietnam and Aceh

• What are the effects on crop productivity and soil properties?

• How does biochar affect plant nutrient availability and water use efficiency?

-100.0

0.0

100.0

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500.0

600.0

thang 1 thang 2 thang 3 thang 4 thang 5 thang 6 thang 7 thang 8 thang 9 thang 10 thang 11 thang 12

ða Nang Qui Nhon Nha Trang Poly. (ða Nang) Poly. (Qui Nhon) Poly. (Nha Trang)

Binh Dinh

Ninh Thuan

Monthly rainfall

Peanuts intercropped with tree crops on sandy soil in Binh Dinh

Irrigation of field crops using hand held hose in Binh Dinh

Cow manure is widely used as soil amendment

Rice husk biochar From Philippines

Rice husk stoves usedin Vietnam, Phang Rang.

Phang Rang rice husk biochar from stove, biochar is doused withwater after being raked from stove- Biochar samples B and C in slide 17

Rice husk stoves are smoke free

Rice husk biocharused by local nurseries for plant propagation

Rice husk stove used in Hanoi – biochar samples D&E in slide 17, D was not doused with water to prevent further burning

Treatments

• Control (nil NPK and manure) • Manure• NPK• NPK+ manureEach with and without biochar; ie 8 treatments NPK (30 N:60 P2O5 :90 K2O); cow manure 5 t/haRice husk biochar 20 t/ha3 reps, random block design, farmer practice field trial.

Biochar trial with peanuts on sandy soil in Binh Dinh, Vietnam

2.2Saturated water content

g/g

27162717CEC cmol(+)/kg

0.120.150.110.220.076Total P %

1.10.4410.830.72Total Nitrogen %

4211463435Total Carbon (Dumas) %

8.28.17.49.1pH (CaCl2)

0.771.51.50.95EC (1:5) dS/m

EDCBA

Rice husk biochar sample

A =Philippines biochar; B &C from rice husk stoves in Phang Rang; D&E residue fromHanoi cooking stove

Above ground biomass of peanut

LSD=0.23

Biomass greater when NPK appliedBiochar increases biomass productionNo significant response to manure

0

0.5

1

1.5

2

2.5

Control NPK Manure Manure + NPK

Dry

mat

ter

bio

mas

s (M

g h

a-1)

Nil RH biochar

RH biocharLSD=0.23

Rice husk biochar on groundnut pod yield (2009)

LSD=0.3

NPK and manure increase yieldBiochar enhances pod yield response to NPK but not manurePeanut yields also increased with biochar application alone

0

0.5

1

1.5

2

2.5


po

d y

ield

(Mg

ha-1

)

Nil RH biochar

RH BiocharLSD=0.3

Potassium uptake

NPK enhances potassium uptakeBiochar enhances fertiliser potassium uptake

0

5

10

15

20

25

30

35

40


K u

pta

ke (

kg h

a-1

)

Nil RH biochar

RH biocharLSD=10.8

Phosphorous uptake

NPK enhances P uptakeBiochar enhances fertiliser P uptake

0

2

4

6

8

10

12

14

16


P u

pta

ke (

kg h

a-1

)

Nil RH biochar

RH biocharLSD=4.1

Nitrogen uptake

N uptake not enhanced by NPK or manure – legume effectBiochar enhances N uptake when manure + NPK applied

0

5

10

15

20

25

30


N u

pta

ke (

kg h

a-1

)

Nil RH biochar

RH biocharLSD=7.7

10

11

12

13

14

15

16

Nil Manure +nil NPK Nil Manure + NPK Manure +nil NPK Manure + NPK

Ave

rag

e fi

eld

wat

er c

on

ten

t m

m (

0-0.

2m)

Nil Biochar

Biochar

Field water content

LSD=2.2

Assessed in field using portable capacitance probe

Field capacity water content

Assessed in laboratory in Vietnam using field samples

0.00

0.05

0.10

0.15

0.20

0.25


Sat

ura

ted

wat

er c

on

ten

t (g

g-1

dry

so

il)

Nil RH biochar

RH biocharLSD=0.04

Increase in soil water holding capacity

Pilot laboratory assessment conducted in NSW

0.00

0.02

0.04

0.06

0.08

0.10

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0.16

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0 20 30 40 60 80

Application rate (Mg ha-1 mixed to 20cm depth)

satu

rate

d w

ater

co

nte

nt

(g g

-1 )

20

22

24

26

28

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80

Soil organic matter % (0-0.2 m)

So

il m

ois

ture

aft

er i

rrig

atio

n m

m (

0-0.

3 m

)

Nil Biochar

BiocharC

NPK M

NPK+M

C

M

NPK NPK+M

C – control, NPK- fertiliser, M - manure

Field capacity water content vs soil organic matter

Field water content higher due to organic matter accumulation which is enhanced in biochar treatments

Conclusions

• Rice husk biochar has – improved uptake of P and K from sandy soils

– increased water holding capacity– Increased yields of peanuts

• Trials are continuing

peter slavich rice husk biochar improves productivity of sandy soils

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